The City of San Diego approves ADUs and JADUs with a ministerial building permit under San Diego Municipal Code section 141.0302, last amended by Ordinance O-22109 effective July 15, 2026 (Information Bulletin 400, January 2026). A single-family lot may add one conversion ADU, one new attached or detached ADU of 150 to 1,200 sq ft and one JADU of up to 500 sq ft; a detached ADU 16 ft or lower may sit on the side and rear property lines outside fire hazard zones, may rise two stories to the zone's height limit (24/30 ft in RS-1 zones), and needs no parking outside the coastal Beach Impact Area. The first two ADUs on a lot pay no citywide development impact fees regardless of size, and DSD plan check plus inspection runs about $5,741 for a 500 sq ft unit and $16,487 for a detached unit over 500 sq ft, plus the $737 General Plan Maintenance Fee (IB-501, August 2026). The ADU Home Density Bonus Program was cut back by O-21989 in August 2025: single-family lots are now capped at 4, 5 or 6 total ADUs and JADUs by lot size, eight RS-1 zones are excluded outside high-resource areas, and each bonus unit owes a Community Enhancement Fee of roughly $17,300 to $20,200. The Coastal Overlay Zone still runs on the older rules until the Coastal Commission certifies O-21989.
Outside city limits? If your property is in unincorporated San Diego County (not within San Diego's boundaries), different rules apply — see our San Diego County (unincorporated) ADU rules.
Zoning & Size Requirements [1][2][3][4][5][6][7][8][9][10]
Yes — San Diego allows ADUs. A detached ADU can typically be up to 1,200 sq ft under current California and San Diego zoning rules.
See what this means for your lot — ask San Diego ADU builders for a quote →
| Allowed Zones | Every base zone and Planned District zone whose use table lists ADUs as a limited use, which is generally every zone that allows residential use, including multiple-dwelling and mixed-use commercial zones (SDMC 141.0302; IB-400). JADUs are allowed only in single-dwelling-unit zones, or on a lot in a multi-unit zone that holds a previously conforming single-family home. Check your zone, Coastal Overlay, fire hazard and transit-priority status on the city's ZAPP map |
| Max Size (Detached) | 1,200 sq ft gross floor area (minimum 150 sq ft) for a new attached or detached ADU (SDMC 141.0302(b)(7)). ADU floor area counts toward the lot's floor area ratio, but one ADU of 800 sq ft or less is always allowed and is exempt from FAR, lot coverage, front setback and open-space rules (141.0302(b)(4)). Garage or carport space under an ADU and an exterior-access mechanical closet do not count toward the 1,200 sq ft (DSD FAQ) |
| Max Size (Attached) | Same 1,200 sq ft cap as detached. A conversion of space inside the existing house or an existing accessory structure has no size cap and may add up to 150 sq ft for entry and egress (141.0302(b)(7)(C)-(D)). ADUs built inside an existing multifamily building have no size cap; HCD's October 2025 findings say a detached ADU on a multifamily lot also cannot be size-capped under Gov. Code 66323 |
| Max Size (JADU) | 150 to 500 sq ft, inside an existing or proposed single-family home or its attached garage; may expand the house by up to 150 sq ft for entry (141.0302(c)). JADU floor area does not count toward FAR. A detached garage cannot become a JADU |
| Max Height | Two stories for a detached ADU or an ADU on an existing accessory structure on a single-dwelling-unit lot; otherwise the ADU follows the base and overlay zone height limit (141.0302(b)(8)). RS-1-1 through RS-1-7 zones allow 24 ft at the setback line rising to 30 ft under the angled building envelope plane (Table 131-04D; SDMC 131.0444); the 30-ft Coastal Height Limit applies near the coast. There is no separate 16-ft or 25-ft ADU cap |
| Max Units | Single-family lot: 1 conversion ADU inside the house or an existing accessory structure + 1 new attached or detached ADU + 1 JADU (141.0302(b)(1), (c)(1)). Existing multifamily building: ADUs in non-living space equal to 25% of existing units (minimum 1) plus up to 8 detached ADUs, not exceeding the number of existing units; proposed multifamily: 2 detached ADUs (141.0302(b)(2)-(3), SB 1211). ADU Home Density Bonus Program (141.0302(d)): one extra market-rate bonus ADU for each deed-restricted affordable ADU inside a Sustainable Development Area, or one of each outside it, with a total cap on single-family lots of 4 units on lots of 8,000 sq ft or less, 5 on 8,001-10,000 sq ft and 6 on 10,001 sq ft or more (Table 141-03A). The bonus program is not available in RS-1-1, RS-1-2, RS-1-3, RS-1-4 or RS-1-8 through RS-1-11 unless the lot is in a High or Highest Resource CTCAC area |
Setback Requirements [1][2][3][4][5][6][7][8][9][10]
San Diego requires a rear setback of about 16 ft for a detached ADU, and parking requirements vary by unit size or location. Owner-occupancy is not required — you can rent it out without living on the property.
| Rear Setback | None for an ADU 16 ft or lower outside a High or Very High Fire Hazard Severity Zone; the Building Code's fire-separation rules may still push the wall off the line. Over 16 ft next to a residential lot: 4 ft or the zone's rear setback, whichever is less. In a High or Very High Fire Hazard Severity Zone: 4 ft at any height (141.0302(b)(9)(C)-(D)). Conversions and same-footprint rebuilds keep the existing structure's setbacks (141.0302(a)(5)) |
| Side Setback | Interior side: same rule as rear, none at 16 ft or under outside fire hazard zones, 4 ft (or the zone minimum if less) over 16 ft next to residential, 4 ft in High/Very High fire zones. Street side: 4 ft or the zone's street-side setback, whichever is less (141.0302(b)(9)(B)). Exterior stairs, decks and balconies must meet the full base-zone setback (DSD ADU page) |
| Front Setback | The base zone's front setback applies (15 to 25 ft in RS-1 zones, Table 131-04D), except that one ADU of 800 sq ft or less may encroach into the front yard (141.0302(b)(4); IB-400). JADUs keep the setbacks of the main house |
| Parking Required | None required for any ADU or JADU (141.0302(b)(10)(A), (c)(7)(A)). The one exception is a lot inside the Beach Impact Area of the Parking Impact Overlay Zone and outside a transit priority area, where one space is required per ADU unless the unit is 500 sq ft or less, attached, in a historic district, in a residential permit parking district, or within a block of a car-share vehicle. No replacement parking when a garage or carport is converted or demolished, except in that same Beach Impact Area. Bonus and affordable ADUs outside a transit priority area need one space each (141.0302(d)(6)). A driveway shorter than 18 ft after a garage conversion must be closed |
| Owner Occupancy | Not required for an ADU (141.0302(b)(11)). A JADU requires the owner to live in the house or the JADU only when the JADU shares a bathroom with the house; a JADU with its own bathroom has no owner-occupancy rule (AB 1154, applied in IB-400 January 2026). A recorded JADU agreement is required before the permit issues (141.0302(c)(1)(F)) |
| Min Lot Size | No minimum lot size for an ADU (141.0302(b)(5)) or a JADU (141.0302(c)(2)); ADUs and JADUs are also exempt from the zone's density limit |
Permit Process & Fees [11][12][13][14][15][16][17]
An ADU permit in San Diego goes through a ministerial, by-right review. Typical timeline: State law: the city must approve or deny within 60 days of a complete application or the ADU is deemed approved (Gov. Code 66314, SB 543 effective January 1, 2026); pre-approved plans get a 30-day review (IB-400). DSD's live dashboard on September 18, 2026 showed about 2 days in intake, 12-18 calendar days for a first review (Structural 12, Combined 16, Planning and Engineering 18), 6-13 days per recheck and 2 business days for issuance; expect one or two correction cycles. Permit fees: IB-501 (August 2026), Table 501A: a detached ADU of 500 sq ft or less, or an attached ADU or JADU up to 1,100 sq ft, pays $3,512.92 plan check plus $2,228.29 inspection for the first 500 sq ft ($5,741.21) and $6.98 + $4.46 per sq ft above that (about $9,173 for an 800 sq ft attached unit). A detached ADU over 500 sq ft is billed at the single-dwelling-unit rate: $8,085.26 plan check plus $8,401.90 inspection ($16,487.16 flat up to 3,000 sq ft including attached accessory structures). Every project also pays the $737 General Plan Maintenance Fee, a $12.16 mapping fee, a 2.5-hour DIF-calculation review (about $442 at the $176.84 hourly rate), $529.71 per new address, water/sewer plan check of $176.57 (no meter change) or $353.13 (new meter), and state seismic and building-standards fees. School district fees apply to any ADU of 500 sq ft or more (IB-146). Express plan check costs $793.95 plus 1.5x the regular plan check fee.
| Approval Process | Ministerial building permit only (Process One); no planning hearing or public notice (SDMC 141.0302; IB-400). Steps: 1) confirm zone, Coastal Overlay Zone, fire hazard zone, transit priority area and Sustainable Development Area on ZAPP; 2) prepare plans per Project Submittal Manual Section 2A: site plan and vicinity map (IB-122), floor and roof plans, elevations, structural plans and calculations, Title 24 energy forms; 3) submit the General Application (DS-3032), Water Meter Data Card (DS-16) and Storm Water Checklist (DS-560) through the online Development Services portal as a Building Construction application; 4) pay project set-up fees, then DSD Planning, Engineering, Structural and (if needed) Fire review; 5) permit issuance, inspections and, for a JADU, a recorded JADU agreement. Inside the Coastal Overlay Zone an ADU that adds habitable area needs a Coastal Development Permit, issued with the building permit in the non-appealable area (SDMC 126.0708(c)); the city's CDP decision on an ADU is not appealable to the Coastal Commission |
| Review Timeline | State law: the city must approve or deny within 60 days of a complete application or the ADU is deemed approved (Gov. Code 66314, SB 543 effective January 1, 2026); pre-approved plans get a 30-day review (IB-400). DSD's live dashboard on September 18, 2026 showed about 2 days in intake, 12-18 calendar days for a first review (Structural 12, Combined 16, Planning and Engineering 18), 6-13 days per recheck and 2 business days for issuance; expect one or two correction cycles |
| Permit Fees | IB-501 (August 2026), Table 501A: a detached ADU of 500 sq ft or less, or an attached ADU or JADU up to 1,100 sq ft, pays $3,512.92 plan check plus $2,228.29 inspection for the first 500 sq ft ($5,741.21) and $6.98 + $4.46 per sq ft above that (about $9,173 for an 800 sq ft attached unit). A detached ADU over 500 sq ft is billed at the single-dwelling-unit rate: $8,085.26 plan check plus $8,401.90 inspection ($16,487.16 flat up to 3,000 sq ft including attached accessory structures). Every project also pays the $737 General Plan Maintenance Fee, a $12.16 mapping fee, a 2.5-hour DIF-calculation review (about $442 at the $176.84 hourly rate), $529.71 per new address, water/sewer plan check of $176.57 (no meter change) or $353.13 (new meter), and state seismic and building-standards fees. School district fees apply to any ADU of 500 sq ft or more (IB-146). Express plan check costs $793.95 plus 1.5x the regular plan check fee |
| Impact Fees | Citywide Development Impact Fees (parks, fire, library, mobility) are waived for the first two ADUs on a lot regardless of size, for any ADU under 750 sq ft, for every JADU, and for any ADU where the owner records an affidavit to live on the property for three years (SDMC 142.0640(b)(1), adopted by O-21439 and certified citywide in 2024). A third or later ADU of 750 sq ft or more pays the citywide DIF from the Public Spaces calculator, and projects with more than one ADU owe Regional Transportation Congestion Improvement Program fees. Bonus and affordable ADUs pay a Community Enhancement Fee equal to the multifamily DIF for the unit's size: on the FY2027 schedule about $17,342 for a unit of 500 sq ft or less and $20,166 at 701-750 sq ft, with the park share added for fee dates on or after May 20, 2026; low- and very-low-income units in High or Highest Resource areas are exempt. A detached ADU that needs its own water meter or sewer connection can also owe Public Utilities capacity charges ($3,047 water and $5,154 sewer per equivalent dwelling unit on the schedule DSD links from IB-501; confirm current amounts). ADUs are not exempt from inclusionary housing fees, which apply once a project reaches 10 units (5 in the Coastal Overlay Zone) |
| Plan Check | Fully digital plan check through the DSD online portal, with a single consolidated resubmittal after all disciplines finish a cycle. Fire sprinklers are required only if the main house has them; a detached ADU never triggers sprinklers in the existing house (141.0302(a)(6)); all bonus and affordable ADUs must be sprinklered (141.0302(d)(5)). A new detached, site-built ADU must include solar panels under the California Energy Code (they may go on the main house); conversions and JADUs are exempt. An ADU over four units on a lot triggers Mobility Choices review, and every ADU needs code-compliant refuse and recycling storage (SDMC 142.0801) |
| Pre-Approved Plans | Yes. Under AB 1332 the city accepts three outside catalogs of pre-approved plans, the County of San Diego Standard ADU Plans, the City of Chula Vista Standard ADU Plans and the City of Encinitas Permit-Ready ADU Plans, with a 30-day review; the plans must be licensed from their designer and re-checked against current codes and the SDMC development standards (DSD ADU page; IB-400). Applicants may also have their own plans pre-approved for others through the master plan process in IB-114a; the city does not publish a count of such plans |
Get Free ADU Quotes in San Diego
Tell us about your project and we'll pass it to ADU builders serving San Diego. Free, no obligation — you choose who to work with. We don't have builders in every area yet; if nobody covers yours, we'll email you to say so.
1. Tell us your project
Takes about a minute.
Takes about a minute.
2. We match local pros
Up to 5 independent local ADU builders — never more, and we tell them nothing you don't submit here.
Up to 5 independent local ADU builders — never more, and we tell them nothing you don't submit here.
3. You choose
Compare quotes, verify license & insurance, hire (or don't). No spam either way.
Compare quotes, verify license & insurance, hire (or don't). No spam either way.
🔒 Your info is secure. We share it only with contractors quoting your project. No spam, no obligation.
Just browsing? Search ADU builders near you by ZIP code.
Construction Costs [18][19][20][21]
Building an ADU in San Diego typically costs $250,000-$450,000 ($375-$600 per sq ft); a garage conversion runs $80,000-$200,000.
See what this means for your lot — ask San Diego ADU builders for a quote →
| Average Build Cost | $250,000-$450,000 |
| Cost per Sq Ft | $375-$600 |
| Garage Conversion | $80,000-$200,000 |
| Prefab ADU (Installed) | $170,000-$325,000 |
Finance Your ADU Project
Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.
Some links on this page are affiliate links. We may earn a commission at no extra cost to you. Learn more
Rental Income Potential [22][23][24]
A 2-bedroom ADU in San Diego rents for around $3,000-$3,300/mo, an estimated 6-10% gross rental yield on a $250,000-$450,000 detached build at $2,200-$2,700/mo (5.9-13% on the raw ranges), before vacancy, taxes and financing; a garage conversion costs a third to a half as much and yields proporti.
| Avg Rent (1 Bedroom) | $2,200-$2,700/mo |
| Avg Rent (2 Bedroom) | $3,000-$3,300/mo |
| Short-Term Rental | No. An ADU may not be rented for less than 31 consecutive days (SDMC 141.0302(a)(8)); a JADU must be rented for longer than 30 days and may not be used for Short-Term Residential Occupancy (IB-400; AB 1154). |
| Est. Annual ROI | 6-10% gross rental yield on a $250,000-$450,000 detached build at $2,200-$2,700/mo (5.9-13% on the raw ranges), before vacancy, taxes and financing; a garage conversion costs a third to a half as much and yields proporti. |
Explore Prefab ADU Options
Prefab ADUs can save 20-40% vs. traditional construction and cut build time in half.
Some links on this page are affiliate links. We may earn a commission at no extra cost to you. Learn more
Recent Law Changes
What's Changed Recently
- Ordinance O-22109 (2026 Land Development Code Update, adopted June 15, 2026, effective July 15, 2026 outside the Coastal Overlay Zone) amended SDMC 141.0302 to exempt state-law ADUs and JADUs from the Climate Action Plan Consistency regulations, require bonus and affordable ADUs to meet them, and clarify that several detached houses on one lot are not a multifamily structure
- FY2027 fee schedule (July 1, 2026) and IB-501 (August 2026): General Plan Maintenance Fee $737, ADU plan check and inspection $5,741.21 for a 500 sq ft unit and $16,487.16 for a detached unit over 500 sq ft; the ADU Home Density Bonus Community Enhancement Fee now includes the Citywide Park DIF for fee dates on or after May 20, 2026 (Resolution R-316744), bringing it to about $17,342 per bonus unit of 500 sq ft or less
- March 11, 2026: the Coastal Commission certified Housing Action Package 2.0 (O-21758), so its ADU rules, including the accessible bonus ADU and the JADU-inside-the-house rule, now apply in the Coastal Overlay Zone; O-21836, O-21989 and O-22109 still do not, and the Commission extended its deadline on the O-21989 amendment (LCP-6-SAN-25-0039-1) to October 2026
- January 1, 2026: SB 543 deems an ADU approved if the city misses the 60-day clock; AB 1154 limits JADU owner-occupancy to JADUs that share a bathroom with the house and sets a 30-day minimum JADU rental term. IB-400 was reissued in January 2026 to reflect the JADU rule
- October 6, 2025: HCD found O-21989 out of compliance with state ADU law on four points (sprinkler wording, no size cap for detached ADUs on multifamily lots, setback versus fire-separation language, tenancy-in-common sales) and gave the city until November 5, 2025 to respond; the cited subsections are unchanged in the July 2026 code, so state law controls where they conflict
- Ordinance O-21989 (final passage July 23, 2025, effective August 22, 2025 outside the Coastal Zone) cut back the ADU Home Density Bonus Program: total ADUs and JADUs on single-family lots capped at 4/5/6 by lot size, the program removed from eight RS-1 zones outside High/Highest Resource areas, one parking space per bonus or affordable ADU outside transit priority areas, 4-ft side and rear setbacks and a two-evacuation-route rule in fire hazard zones, a Community Enhancement Fee, and AB 1033 condo sales of ADUs. The program had produced 875 of the 5,720 ADUs permitted in 2021-2024 (Planning Commission Report PC-25-016)
Tips for Building an ADU in San Diego
- Keep a detached ADU at 16 ft or lower and outside a fire hazard zone and it can sit on the side and rear property lines; the only limit is the Building Code's fire-separation rule, so plan a rated wall or a few feet of clearance rather than a 4-ft setback
- Stay at 800 sq ft or less for one ADU: it is exempt from floor area ratio, lot coverage, open space and the front setback even when the lot's floor area is used up (SDMC 141.0302(b)(4))
- Size matters for fees: a detached ADU of 500 sq ft or less, or an attached ADU up to 1,100 sq ft, is billed at the remodel rate (from $5,741), while a detached unit of 501 sq ft or more is billed as a new house ($16,487); budget the $737 General Plan Maintenance Fee and school fees on units of 500 sq ft or more either way
- Your first two ADUs owe no citywide development impact fees at any size, and any further ADU is also exempt if you record a three-year owner-occupancy affidavit before the permit issues (SDMC 142.0640(b)(1))
- Use ZAPP before you design: the Coastal Overlay Zone runs on older rules and may need a Coastal Development Permit, High and Very High Fire Hazard Severity Zones force 4-ft setbacks, and the Beach Impact Area is the one place that still requires parking
- For a bonus project, check the base zone (no RS-1-1 to RS-1-4 or RS-1-8 to RS-1-11 outside High/Highest Resource areas), count the 4/5/6 lot-size cap including the JADU, and price in sprinklers, one parking space outside a transit priority area, the recorded affordability agreement with the Housing Commission (10-year very-low or low income, 15-year moderate) and a Community Enhancement Fee of roughly $17,300-$20,200 per bonus unit
- Underwrite on 31-day-plus leases ($2,200-$2,700/mo for a one-bedroom in 2026); short-term rentals are barred for ADUs and JADUs, but a qualifying ADU can later be condo-mapped and sold separately under AB 1033
- Cost basis (2026-09-19 re-verification): avg build cost: $250,000-$450,000 for a new detached ADU all-in (design, permits, site work and utilities), $200,000-$400,000 for an attached ADU and $110,000-$200,000 for a JADU, per San Diego industry guides dated March-September 2026. A 2025 city staff report noted that 98% of the 4,388 ADU projects permitted in 2021-2024 built 1 to 3 units | cost per sqft: $375-$600 per sq ft all-in for new construction, with small units at the top of the range (about $600/sq ft at 500 sq ft, $375-$425/sq ft at 1,000-1,200 sq ft); garage conversions $200-$400 per sq ft (industry guides, 2026) | garage conversion: $80,000-$200,000 for a typical one- or two-car garage (industry guides updated June-September 2026; most two-car conversions land at $95,000-$180,000). Conversions keep the garage's existing setbacks, need no replacement parking outside the coastal Beach Impact Area and skip the solar requirement, but a driveway left shorter than 18 ft must be closed | prefab adu: $170,000-$325,000 installed for a 500-900 sq ft modular or manufactured unit ($260-$370 per sq ft, industry guide reviewed June 2026); foundation, utility trenching and site work are extra. A manufactured ADU is exempt from the solar-panel requirement, and IB-501 lists a flat $5,776.62 plan check plus $3,310.82 inspection for a manufactured or factory-built single dwelling unit (ask DSD whether your prefab ADU is billed at that tier) | avg rent 1br: $2,200-$2,700/mo (Zumper Septe
ADU Builders in San Diego
Looking for an ADU builder in San Diego? ADU projects need a contractor experienced with local zoning, the permit process, and utility connections — not every general contractor has built one. We match San Diego homeowners with experienced local ADU contractors who provide free, no-obligation quotes. Getting at least three bids typically saves 20-40% on the same scope.
Sources & References
All data on this page is sourced from official government records and verified market data. View our full methodology.
- SDMC Chapter 14, Article 1, Division 3, Section 141.0302 Accessory Dwelling Units and Junior Accessory Dwelling Units (7-2026 edition, amended by O-22109 effective 7-15-2026) Municipal Code — Accessed 2026-09-19
- Information Bulletin 400: Accessory Dwelling Unit / Junior Accessory Dwelling Unit (January 2026) | City of San Diego Development Services Planning Department — Accessed 2026-09-19
- Accessory Dwelling Unit / Junior Accessory Dwelling Unit program page (setbacks, pre-approved plans, FAQ) | City of San Diego Development Services Planning Department — Accessed 2026-09-19
- SDMC Chapter 13, Article 1, Division 4, Table 131-04D and Section 131.0444 (RS zone setbacks and 24/30 ft height) Municipal Code — Accessed 2026-09-19
- Ordinance O-21989 N.S. (final passage July 23, 2025) amending the ADU and JADU regulations municipal — Accessed 2026-09-19
- Strikeout Ordinance O-22109 N.S. (2026 Land Development Code Update, final passage June 15, 2026), Sections 141.0302 and 142.0640 municipal — Accessed 2026-09-19
- City Council Adopts Reforms to Accessory Dwelling Unit Program (Inside San Diego, June 18, 2025) municipal — Accessed 2026-09-19
- Planning Commission Report PC-25-016, ADU and JADU Regulation Amendments (April 24, 2025), Tables 1 and 3 Planning Department — Accessed 2026-09-19
- Coastal Commission staff report Th11c, time extension for LCP-6-SAN-25-0039-1 (ADU Density Bonus Program), October 9, 2025 Government Data — Accessed 2026-09-19
- Coastal Commission San Diego Coast District Deputy Director's Report W18, March 11, 2026 (certification of LCP-6-SAN-24-0010-1, Housing Action Package 2.0) Government Data — Accessed 2026-09-19
- Information Bulletin 501: Fee Schedule for Construction Permits-Structures (August 2026), Tables 501A and 501D | City of San Diego Development Services Planning Department — Accessed 2026-09-19
- SDMC Chapter 14, Article 2, Division 6, Section 142.0640(b)(1) Development Impact Fee exemptions for ADUs (7-2026 edition) Municipal Code — Accessed 2026-09-19
- Fiscal Year 2027 City Planning Department Fee and Deposit Schedule (General Plan Maintenance Fee, Citywide DIF rates, ADU Home Density Bonus Community Enhancement Fee) Government Data — Accessed 2026-09-19
- Permit Processing Timeline (intake, review and issuance dashboard, data as of September 18, 2026) | City of San Diego Development Services Planning Department — Accessed 2026-09-19
- Information Bulletin 146: School Fees (September 2026) | City of San Diego Development Services Planning Department — Accessed 2026-09-19
- Schedule for Water and Sewer Fees (capacity charges per EDU) | City of San Diego Public Utilities Government Data — Accessed 2026-09-19
- Strikeout Ordinance O-21439 N.S. (Housing Action Package 1.0, 2022), Section 142.0640(b)(1) ADU impact fee exemptions municipal — Accessed 2026-09-19
- Cost to Build an ADU in San Diego (2026), updated March 2026 | Snap ADU industry — Accessed 2026-09-19
- How Much Does an ADU Cost in San Diego? (2026 Guide), reviewed June 14, 2026 | ADUVerified industry — Accessed 2026-09-19
- ADU Cost San Diego 2026: Prices and Financing, updated September 6, 2026 | Lars Remodeling industry — Accessed 2026-09-19
- Garage Conversion Cost in San Diego (2026 Guide) | Lumina Builders industry — Accessed 2026-09-19
- HUD FY 2026 Fair Market Rents, San Diego-Chula Vista-Carlsbad, CA MSA (FY26_FMRs.xlsx) Government Data — Accessed 2026-09-19
- Average Rent in San Diego, CA (September 2026) | Zumper Market Data — Accessed 2026-09-19
- Average Rent in San Diego, CA (updated August 31, 2026) | RentCafe Market Data — Accessed 2026-09-19
- HCD findings letter, Review of San Diego's ADU Ordinance O-21989 under State ADU Law (October 6, 2025) Government Data — Accessed 2026-09-19
- CA SB 543 (2025-2026), chaptered October 10, 2025: 60-day ADU review and deemed approval (Gov. Code 66314, 66317) Government Data — Accessed 2026-09-19
- CA AB 1154 (2025-2026), chaptered October 10, 2025: JADU owner-occupancy only with shared sanitation, 30-day minimum rental Government Data — Accessed 2026-09-19
- California HCD Accessory Dwelling Unit Handbook and ordinance review program Government Data — Accessed 2026-06-28
Frequently Asked Questions
Can I build an ADU in San Diego?
Yes. ADUs are allowed in Every base zone and Planned District zone whose use table lists ADUs as a limited use, which is generally every zone that allows residential use, including multiple-dwelling and mixed-use commercial zones (SDMC 141.0302; IB-400). JADUs are allowed only in single-dwelling-unit zones, or on a lot in a multi-unit zone that holds a previously conforming single-family home. Check your zone, Coastal Overlay, fire hazard and transit-priority status on the city's ZAPP map in San Diego. The maximum size for a detached ADU is 1,200 sq ft gross floor area (minimum 150 sq ft) for a new attached or detached ADU (SDMC 141.0302(b)(7)). ADU floor area counts toward the lot's floor area ratio, but one ADU of 800 sq ft or less is always allowed and is exempt from FAR, lot coverage, front setback and open-space rules (141.0302(b)(4)). Garage or carport space under an ADU and an exterior-access mechanical closet do not count toward the 1,200 sq ft (DSD FAQ). Owner-occupancy is not required, so you can rent out the ADU.
How much does an ADU cost in San Diego?
ADU construction in San Diego typically costs $250,000-$450,000. Garage conversions run $80,000-$200,000, and prefab ADUs cost $170,000-$325,000.
How much can I rent an ADU for in San Diego?
Average ADU rents in San Diego are $2,200-$2,700/mo for a 1-bedroom and $3,000-$3,300/mo for a 2-bedroom unit.
Do I need parking for an ADU in San Diego?
None required for any ADU or JADU (141.0302(b)(10)(A), (c)(7)(A)). The one exception is a lot inside the Beach Impact Area of the Parking Impact Overlay Zone and outside a transit priority area, where one space is required per ADU unless the unit is 500 sq ft or less, attached, in a historic district, in a residential permit parking district, or within a block of a car-share vehicle. No replacement parking when a garage or carport is converted or demolished, except in that same Beach Impact Area. Bonus and affordable ADUs outside a transit priority area need one space each (141.0302(d)(6)). A driveway shorter than 18 ft after a garage conversion must be closed. Check with San Diego planning department for the latest California ADU parking rules, as many states have relaxed requirements in recent years.
How long does it take to get an ADU permit in San Diego?
The permit review timeline in San Diego is State law: the city must approve or deny within 60 days of a complete application or the ADU is deemed approved (Gov. Code 66314, SB 543 effective January 1, 2026); pre-approved plans get a 30-day review (IB-400). DSD's live dashboard on September 18, 2026 showed about 2 days in intake, 12-18 calendar days for a first review (Structural 12, Combined 16, Planning and Engineering 18), 6-13 days per recheck and 2 business days for issuance; expect one or two correction cycles. Permit fees: IB-501 (August 2026), Table 501A: a detached ADU of 500 sq ft or less, or an attached ADU or JADU up to 1,100 sq ft, pays $3,512.92 plan check plus $2,228.29 inspection for the first 500 sq ft ($5,741.21) and $6.98 + $4.46 per sq ft above that (about $9,173 for an 800 sq ft attached unit). A detached ADU over 500 sq ft is billed at the single-dwelling-unit rate: $8,085.26 plan check plus $8,401.90 inspection ($16,487.16 flat up to 3,000 sq ft including attached accessory structures). Every project also pays the $737 General Plan Maintenance Fee, a $12.16 mapping fee, a 2.5-hour DIF-calculation review (about $442 at the $176.84 hourly rate), $529.71 per new address, water/sewer plan check of $176.57 (no meter change) or $353.13 (new meter), and state seismic and building-standards fees. School district fees apply to any ADU of 500 sq ft or more (IB-146). Express plan check costs $793.95 plus 1.5x the regular plan check fee.
Ready to Build in San Diego?
Get free, no-obligation quotes from top-rated ADU contractors in San Diego.
Get Free Quotes →Build ADUs in San Diego?
Homeowners read this page while planning, then ask us to connect them with a local builder. We pass those requests to builders who cover San Diego — a flat fee only on the leads you accept, no subscription, and you contract directly with the homeowner.
See who's waiting in California →